Question

Which of the following is not a step in the process of breakdown of food by lysosomes?

• A. Exocytosis
• B. Digestion of worn-out organelles
• C. Formation of phagosome
• D. Endocytosis

Answer 1

The correct option is B Digestion of worn-out organelles

Breakdown of ingested food in cells occurs in 4 steps: i. Endocytosis - Endocytosis is the entrapment of the food particle into the cell’s cytoplasm by the formation of a food vesicle around the particle. ii. Formation of phagosome - The phagosome is the vesicle which is formed by the fusion of the cell membrane around the particle. iii. Breakdown of food - The lysosome fuses with the vesicle, releases its enzymes and the food particle is then broken down by the action of enzymes. iv. Exocytosis - The undigested food is then finally removed from the cell via exocytosis of the vesicle.